关键词: 耦合物理场CVI, C/C复合材料, 微观结构, 快速增密, 机理

Abstract: in the felt forming the grads of temperature and electromagnetism, C/C composites were fabricated by chemical vapor infiltration (CVI) with
multi-factor coupling physical fields. The textures of pyrolytic carbon were observed by a polarization microscope(PLM), and the graphitization degree and
minicrystal size of the C/C composites were analized by XRD. All samples were fabricated at one cycle. The densities of the matrix were measured by on-line
coupling with resistance.At last,the mechanism of multi-factor coupling physical fields and deposition of carbon was discussed. The results
show that, with multi-factor coupling physical fields, the rate of deposition of pyrolytic carbon can be improved greatly, and when deposited for 20h,
C/C composites with densities of more than 1.7g/cm³ will be obtained. Through optimizing the infiltration conditions, some microstructures of pyrolytic carbon can
be obtained ,range from rough laminar,smooth laminar, and banded structure. The graphitization degree of the rough laminar can be over 77% after heat
treatment at 2300℃ for 2h.

Key words: multi-factor coupling physical fields CVI, carbob/carbon composites, rapid densifi-cation, microstructure, deposition mechanism